Chapter 5. AGEING AND LEARNING
AGE PATTERNS
As we age, our ability to learn and remember changes.
Due, for example, to ‘infantile amnesia’, most of us can’t
remember anything about being a toddler. We don’t know
why. The memories might still be there but not easily accessible.
Or it could be that the circuits holding those earliest memories are
overwritten when new brain cells are produced and integrated.
Around adolescence, our prefrontal cortex – which controls
planning, decision-making and working memory – develops
significantly. Our ability to plan for the future improves and
we can process more information when deciding between
different options.
Our ability to remember new information peaks in our
20s, and then starts to decline noticeably from our 50s or 60s.
Because the hippocampus is one brain region that continues
producing new neurons into adulthood, it plays an important
role in memory and learning. The section called the dentate
gyrus is where the new neurons are created. Many are
produced during childhood, but activity in the dentate gyrus
slows down as we age. The reason for memory decline isn’t
known but may involve this decreased rate of neurogenesis.
Dementia, which is experienced by 10% of people
older than 65, occurs when abnormal proteins accumulate
inside and around neurons. These proteins are thought
to affect our memories by killing the synapses and
ultimately the neurons that hold memories together.
THERE’S NO escaping it: cognitive
function declines with age. But it’s
not all bad news. An important key to
slowing decline may lie in exercising
not only the brain, but also
the body.
QBI’s Professor Perry
Bartlett was one of the
first people to discover
that the adult brain
contains stem cells
capable of making new
neurons. As the brain ages,
these stem cells lose their
ability to produce new
neurons, causing cognitive
function to decline.
Ground-breaking research by Prof
Bartlett and Dr Daniel Blackmore
Exercise and ageing
recently identified that exercise is
able to increase production of new
brain cells and improve learning and
memory. They are now heading up
a clinical trial monitoring
300 people aged 65 and
older to identify the right
amount, intensity and type
of exercise that leads to
cognitive improvement in
the ageing brain. “This will
be the most comprehensive
analysis yet of why
exercise is beneficial,”
Prof Bartlett explains.
“Ultimately, we would hope
to have clear public health guidelines
as to how exercise can both prevent
and reverse dementia.”
A key to SLOWING
DECLINE may lie
in exercising not
only the brain,
but also the
body.